α-Substituted phenylacetic acid compounds (see, for example, Patent Document 1) and azole compounds (see, for example, Non-Patent Document 1) are conventionally known as active ingredients of agents for controlling plant diseases. Nevertheless, there is a continuing need for more highly active agents for controlling plant diseases.    Patent Document 1: WO 95/27,693    Non-Patent Document 1: “The Pesticide Manual-14th edition” published by BCPC, ISBN: 1901396142